In vessel surgery, it has become increasingly useful to use by-passes, for example, constricted vessels can be replaced by healthier ones that are coupled in parallel or connected to other vessel locations. Until now, vessels have been joined with a common technique of sewing the vessels together with sutures.
More recently, anastomosis rings have become available for joining blood vessels, for example, in end-to-side anastomosis. This technique is accomplished by puncturing a small cut in a first blood vessel, which is then flared and placed over the pins of an anastomosis ring. The flared joint can then be attached with a complementary anastomosis ring to the end of a second vessel. In this way, it is possible to conduct a branching or by-passing procedure in considerably less time than with conventional suturing techniques. The use of anastomosis rings, in this fashion, is known to diminish the risks to the patient and conserve resources.
Regretfully, the use of anastomosis rings for end-to-side joining of blood vessels is not entirely without draw backs. It has been found that the application of the anastomosis rings to a vessel steals material from the vessel and results in a constriction in its diameter. This is undesirable, since one of the objectives of a by-pass is to improve flow, and not to replace one impedance to flow with another. Accordingly, there is a need for a technique and instrument for eliminating constrictions caused by anastomotic ring placement.